Type inferrence flagged incorrectly

[cznic]

(13:48) jnml@fsc-r550:~/src/tmp/golint$ cat main.go 
package main

type b []byte

func foo() []byte { return nil }

func main() {
        var x b = foo()
}
(13:49) jnml@fsc-r550:~/src/tmp/golint$ golint main.go 
main.go:8:8: should omit type b from declaration of var x; it will be inferred from the right-hand side
(13:49) jnml@fsc-r550:~/src/tmp/golint$ 

[dsymonds]

Yes, there's a large class of things that golint gets wrong for that (the more common is when the LHS is an interface). Still, it's relatively unusual to write code like that, and you can work around it easily enough (write "var x = b(foo())"). It'll need the full typechecking wired up to do it completely correctly, and that won't happen for a while.

[peterbourgon]

Same root cause for this symptom?

package main

import (
    "math"
)

func main() {
    var i uint64 = math.MaxUint64
    println(i)
}

$ golint a.go
a.go:8:8: should omit type uint64 from declaration of var i; it will be inferred from the right-hand side

—

package main

import (
    "math"
)

func main() {
    i := math.MaxUint64
    println(i)
}

$ golint b.go
$ go run b.go
# command-line-arguments
./b.go:8: constant 18446744073709551615 overflows int

[dsymonds]

Yes, that's the same cause.

[robert-zaremba]

bumping up.

Other example

var maxTime int64 = 5 * 24 * 3600

and I want to use maxTime with other int64 values. It is ugly to write

var maxTime = int64(5 * 24 * 3600)

[mewmew]

Another example for the record:

Link to p.go: http://play.golang.org/p/9DvFBwDYlc

$ go install play/p
$ golint play/p2
play/p/p.go:8:12: should omit type T from declaration of var mask; it will be inferred from the right-hand side

Link to update version of p.go: http://play.golang.org/p/sGuwidVxjN

$ go install play/p
# play/p
play/p/p.go:9: invalid operation: t & mask (mismatched types T and int)